In his famous "The Work of Art in the Age of Mechanical Reproduction" Walter Benjamin uses the concept of "aura" to designate the quality of originality and authenticity of the aesthetic experience of an original work of art (to learn more about Benjamin's concepts of aura and authenticity see separate post).
According to Benjamin and the thesis he promotes on "The Work of Art in the Age of Mechanical Reproduction" advanced reproduction and distribution techniques that have evolved in the early 20th century have had a significant impact on the art world. What Benjamin is arguing is that the social function of art has changed with the appearance of technology based art like the cinema. This historical process is explained by Benjamin as the loss of the aura and the degeneration of art which has its aesthetic value determined by its originality or one-timeness.
Photography and then cinema lead the way in the degeneration of the aura. These mediums are, according to Benjamin, the central agents in the process of the transformation of art's social function. Mechanical reproduction is faster: faster to produce, faster to distribute. Machinery such as the camera assumes the place of the artist of craftsman and denies any authorship of a unique original.
Mechanical reproduction bridges the space-time gap between the subject and object of the aesthetic experience. It makes the artwork the viewer's contemporary. The loss of the aura is accompanied and affected by the mass reproduction and the "flattening" of the work of art. Mass reproduction of art sets the stage for a new type of human perception: collective perception which according to Benjamin allows for the politicization of art later in "The Work of Art in the Age of MechanicalReproduction".
The medium for Walter Benjamin is not only the message but also an agent of social and political change. The new type of mechanically reproduced work of art is widely accessible for the masses and it thus positions people in a whole new relation to it. Benjamin, in chapter 12 of "The Work of Art in the Age of Mechanical Reproduction", gives the example of how cinema is consumed when situated in a group on the one hand and as anonymous on the other hand. The crowed regulated itself and in that the individual's position towards the film. This notion is obviously linked to the Frankfurt School notion about the culture industry.